Common defects in the most popular rotary screen p

2022-07-23
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Common defects in circular printing and their prevention

some common defects in circular printing and their preventive measures:

1. Knife line (wide strip) when there is a small notch on the scraper or adheres to garbage impurities, when the circle rotates, it will produce uneven color scraping, resulting in deep flower position. As long as we grasp some shallow strip knife lines with its skills

measures:

(1) reasonably select and use scraper. For large pattern area, select thick and wide blades; for small pattern area, select thin blades, and scrape the color paste with light scraper pressure and appropriate scraper angle to reduce the friction resistance between the scraper and the circle. The scraper shall be kept straight to ensure that the force on the scraper is uniform and the scraping slurry is consistent

(2) ensure the round quality. Before using the circle, the clarity of the hole and the smoothness of the wall shall be carefully checked, and the latex thickness during the glue scraping shall be controlled to prevent the glue from entering the inner wall

2. Exposed background when printing large-area patterns, it is easy to see that some patterns have a shallow color, show a small white core or cannot be printed with color paste to expose the background color

measures:

(1) reasonably select circles. The large flowers on the ground use 40 ~ 80 meshes, and the medium-sized ones are very important for cleaning after each use. The patterns use 60 ~ 80 meshes, the small patterns use 80 ~ 100 meshes, and the fine patterns use 125 ~ 150 meshes. At the same time, adjusting the pressure and angle of the scraper can improve the bottom exposure

(2) reasonably select and use paste. It is advisable to select the original paste with low protection degree and good rheological property for the maintenance of various parts of the hydraulic system of the testing machine and the hydraulic system. The original paste or residue that has been stored for a long time and hydrolyzed cannot be used

3. Plugging (embedding, plugging) because the holes of circular printing are embedded with fiber fluff or insoluble particles of printing paste or other impurities, the pattern holes are blocked and the printing paste is prevented from penetrating outward, so that the fabric pattern has little or no paste locally

measures:

(1) improve the quality of semi-finished products. Improve the smoothness of the cloth surface, install a brush at the cloth inlet, and brush away the impurities and fluff on the cloth surface

(2) strictly adjust the slurry. Dyes, chemicals and additives shall be fully dissolved and filtered during sizing to ensure the cleanness of the color paste and prevent the mixing of various particles and impurities

4. Round crease printing uneven scraping caused by round bumps or creases due to careless operation, and there will be regular horizontal line or block like deep and light colors with the same shape and round circumference on the fabric surface

measures:

(1) when the circle is placed on the bracket, adjust the height of the idler to keep the distance between the circle and the printing guide constant at 0.3mm, so as to avoid the deformation of the circle caused by the pressure of the scraper and causing wrinkles

(2) before the round operation, the round must be tensioned evenly to keep the round with sufficient rigidity and elasticity, so as not to twist and wrinkle due to single-sided transmission under the pressure of the printing scraper

(3) the sharp contact angle between the two ends of the printing scraper blade and the circle must be cut into an arc and polished to avoid damaging the circle due to excessive resistance

5. For the detection of multiple pairs of magnetic core materials, the special fixture made by Jinan period experimental machine was selected. The same color spots with regular spacing, similar to the circumference, etc. appeared on the printed fabric. The reason is that the adhesion of the circular photosensitive adhesive film is poor. When scraping, the printing scraper directly rubs with the circle, and the adhesive layer with poor adhesion peels off from the hole to form sand holes

measures: the circle should be thoroughly cleaned before applying the photosensitive adhesive. It is better to use the mixture of detergent and detergent powder. After washing, dry the water with low-temperature circulating air. When applying the photosensitive adhesive, keep the room clean to prevent dust particles from adhering to the wet adhesive layer

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